1. Field of Invention
The present invention relates to a LED circuit. More particularly, the present invention relates to a LED circuit with high dimming frequency.
2. Description of Related Art
LEDs are estimated to be four times as efficient as conventional incandescent lights. They are also claimed to be more economically sound than compact fluorescent bulbs that contain harmful mercury and are supposed to last a lot longer than the conventional lighting. Thus, LEDs may become the mainstream of the lighting technology.
A conventional driver of the LED circuit operates at a frequency lower than 1 KHz. Due to the low operation frequency, people can hear the noise of the vibration generated by the LED circuit. Therefore, it's suitable to make the operation frequency higher. However, it's hard to maintain the linearity relationship between the current of the LEDs and the dimming signal of the driver when the frequency of the dimming signal is higher. The loss of the linearity makes the brightness of the LED circuit lower, which is an undesirable result.
Accordingly, what is needed is a LED circuit that works under high frequency without losing the linearity to keep the brightness appropriate to overcome the above issues. The present invention addresses such a need.